Dataset parameters and report parameters

In BIRT, there is a very important distinction between dataset parameters and report parameters. This distinction can be confusing at first, which is why I want to discuss it now. The difference is one of scope and function. A report parameter has a global scope and can be used in a number of different ways in reports. Report Parameters are user facing variables that prompt the user for input. If you have ever worked with a traditional reporting language, think of report parameters as a global variable, combined with a standard input statement that will fill that variable with a value.

Dataset parameters, on the other hand, are limited in scope to within the dataset that they are declared in. Dataset parameters work more like bind variables in a relational database management system, or a prepared query in a data aware programming model, such as ADO or JDBC. Dataset Parameters are typically linked to Report Parameters to retrieve their values, but...